沢|さわsawa[2]odaka (tail-high)

1. nounmountain stream; valley; dale
2. nounwetlands; swamp; marsh

• Related沼沢しょうたくWrittenWritten/formal and academic in tone, for marshes and bogs; 「沢」 usually means a mountain stream or valley, though it can also refer to low-lying wetlands.
• Related沼ぬまNeutralA pond or marsh, and by extension a hobby you get sucked into, as in 「沼にハマる」; 「沢」 is mostly a mountain stream or valley.
• Related湿原しつげんNeutralGrassland waterlogged with freshwater, as in 「尾瀬湿原」; 「沢」 is mostly a mountain stream or valley.
• Related沼地ぬまちNeutralMarshy, muddy ground, as in 「沼地を歩く」; 「沢」 usually means a mountain stream or valley, but can also mean low-lying wetlands.
• Related湿地しっちNeutralGround that is damp and humid, as in 「湿地帯」; 「沢」 is mostly a valley with a small mountain stream running through it.
• Related沼沢地しょうたくちWrittenWritten/formal and academic, for marshy terrain; 「沢」 usually means a mountain stream or valley, though it can also refer to low-lying wetlands.
• Related湿地草原NeutralGrassy wetland; 「沢」 usually means a mountain stream or valley, and can also refer to low-lying wetlands.
• AntonymやまNeutralThe antonym in the mountain-versus-valley pairing: 「山」 is the mountain or ridge itself, as in 「山と沢」.

Use 「沢」 for a mountain stream or the valley it runs through, as in 「沢登り」, and for low-lying wetlands. For marshes pick 「沼」 or 「沼地」, for grassy wetlands 「湿原」, for damp ground 「湿地」; the opposite of a valley is 「山」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （さわ）山間さんかんに流ながれる小川おがわ。